Method of producing jointures for vulcanized rubber parts.



QT AVAILABLE COPY L L. MAHONEY. I 0 OF PRODUCING JOINTURES FOR VULCANi AP PUCATION FILED MN. \5, 1918.

1 Patented. Dec. 31,1918. 7

ZED RUBBER PARTS.

3:, wva/Mloz, ..Z 5. krellzakL/llakazzay $51 hi3 m ce ovum. I 7

INDIA RUBBER GLOVE NECTICUT.

TED STATES PATENT OFFICE. Y

evenness, ooe,

' JEREMIAH L. MAHONEY, on NEW HAVEN, oomunoriovrfixssmnon To THEGOODYEARS;

MANUFACTURING COMPANY, A CORPORATION or CON- METHOD PRODUCING JOINTURES FOR VULCANIZEJD RUBBER PARTS.

Application filed January 15, 1918.

To all whom it may concern:

Be it known that I. JEREMIAH L. MA.

nonnm, a citizen of the United States, residing at New Haven, county of New Haven,

State of Conne'rtirut, have invented vermin her Forts of which the following is a full,

' and has for its principal object thejoining of mhher parts that have been'previously vulcanized, by operations that are carried out from one. side only of the-rubber partsi A t'wther object is to maintain, in the verrying out of such a method, a pro-deter mined relationship in the positions of the parts to be joined.

A further ohjei-t is to provide a method to facilitate speed and reduee the apparatus needed in melting the iointure of the vulcanized rubber parts.

/Vhile my invention is not confined to any =spo 'ilio ztrtule of manufacture, it is however especially adapted for use in the manufaeture of hollow ruhher articles in whi"h are for temporary onenings tor the withhrough oi? the forming core-s about wid h the articles are ulcanized and winch openings must be subsequently pernnmentlv vies-ed to produre the finished urticles. The invention is more espewielly (l3: rented to the u'isnnfwture of hot water hot t les and similar qrtiels wherein the filling no l: too small to permit oi? the with drawn! of the Pore therefrom.

This :tppli-wetion is e continuation in part of upplimt ou Serial No. 169,818, filed by me Mov 21st. 1917 for improvements in molds ulnd proresses for vuleanizing rubber artie For mmonience and to fa ilitate a clear understanding of the advantages gained, my

invention will therefore he des ribed and lllllRlI'RiMl in ronne'tion with the production of a hot water bottle. from which description breeder s 'ope and application will of eu o ie apparent.

"il' i'lx the shore and other objects in view. \vhi -h will readily appear as the nature of the invention is heifer understood. the same (mfilFtS is he novel steps. combination, and

Specification of Letters Itatent.

Patented Dec. 31, 191i,

Serial No. 211,904.

arrangement hereinafter more.

scribed, illustrated, and claimed. 5.5

Referring to the drawings showingitppa ratus designed for the carrying out of my method- Figure 1 is a front View of the lower mold section, and core. f

Fig. 2 is a vertical central sectional View of Fig. 1. l I

Fig. 3 is a sertionul View taken. on the line 3-3 of Fig. 1.

Fig. 4 is a front View of a closing mold sertion showing the base of the bottle supported therein.

Fig. 5 is an enlarged sectional view along the line 5-5 of Fig. 4.

Fig. 6 is a fragmental View of one half of the finished joint and,

Fig. 7 is e sectional View similar to Fig. 5 but sho dng a modification. s I

Hot water bottles of the type here referred to are usually formed from sheeted vuleanizable rubber out or died out to form blanks of the desired patterns to form the several parts of the bottle, such for instance as the ne' ln tub and body portions. These are assembled in a mold about it su table core and yulcenized after whi"h the core is withdrawn throuq'h a suitable opening and the opening finally closed. In the present instan e, the blanks are cutfrom sheeted rubber stock to form the sides 1 1, the ne' k portion 2 and the tab 3. These are assembled iuthe mold sectio s -42 about t core 5 which has a removable uortion' for formlugthe ne"'k 2 of the bottle which maifrloe of any desired or Well-known construction The. rore 5 is provided with a tonoueti which protrudes throurrh the base of the bottle and serves to maintain the edges so arated during" vulcanization of the bo tle, in order to "ide an opening for finally with drawing the (ore therethrough. The tongue 6 is made omparatively .long to provide a hand-hole 7 to facilitate the withdrawal of the (ore from the bottle. It is not essential however that the hole or slit for thlwith-s r drawal'of the bottle be formed in the bottle previous to its vulcanization, for-it is ohri-- ons that the sides mav be -wilcanized lZ'l'(fO?l-- tact throughout their entire edges nix-"tai suitable openiogor slit vut'after vulvuntzw i tion I sition and the mold sections brought together in the usual manner. During this operation, the margins of the side walls are turned inwardly toward each other and finally when the mold sections are closed they contact.

along their edges toform a butt joint. The stock at these marginal portions isslightly thickened to provide a correspondingly increased area for the abutting surfaces forming the joint. In the present instance, I prefer to provide a still thicker portion along the bottom edges8-8 about the slit 9 in order that a sufliciently broad abutting joint may be subsequently made when closing the slit to'give the required strength thereto, as will later more 'fully appear. Moreover in the preferred embodiment, the slit or opening 9 is formed with more or less rounding or Y-shaped end portions which give further strength to the joint and the tongue 6 is conveniently formed to mold the slit with converging opposed walls to form the V-sliaped ends. The wall of the tongue 6 instrumental in forming the openingmay be of any desired thickness and the outer face of the margins about the opening may be in itsoriginal shape slightly bulged out-' wardly so that when the closure is effected the outer opposing surfaces of the margins about the opening will be brought to assume relative positions corresponding to the relative positions of-the margins about the remain- 1 der. of the body 'portionof the bottle inorder to'preserve uniformity of appearance about'the entire body of the bottle. In Fig.

' stituting the bottle.

- 1 2, this feature is shown by bulging the thickthat when the slit9 is closed these bulging ened portions 8-8 slightly outwardly so faces will be brought slightly closer together to correspond with the margins which were vulcanized together simultaneously with the vulcanization of the rubber material',lcon Of course, in shaping the margins about the slit to produce the desired final result much will depend upon the quantity of'vulcanizable rubber which is to be inserted in the slit. For instance, if only rubber cement is to be used the bulged portions would be sufficient to approximately account for the thiclmess of the portion 6 forming the opening. While if a strip of vulcanizable' rubber. is used to form the'closure, and the strip in its finally compressed.

tirely from one side of the bottle and as it further contemplates the definite relative positioning of the p-rrts about the opening, I provide a closing mold of special construcwhich tension acts to draw or pull and to tion comprising the sections 10-10. The mold sections are provided with cavities 11'11 adapted to receive the portion of the bottle containing the slit or opening and to afford supporting walls to engage the parts to be joined from corresponding sides to accurately aline them with each other. It is of primary importance that the joint be so nicely produced and the opposed parts so accurately register that besides giving the required strength to withstand the pressure test which the bottle must be subjected to, there will be little or no manifestation of the existence of a joint at this portion, in order to make a readily salable article.

The joint forming the closure is usually made with the aid of pressure, previous to or during final vulcanization, and this pressure has a tendency to force the parts to be joined away from the exterior supporting wall provided by the mold sections so that the opposing edges will not accurately register in the final product,.thereby besides making a weak joint also producing an unsightly and unsalable article. It is customarily the practice to provide an interior support pressing on the inner sides of the parts to be joined to insure a continual uniform pressure and positive registering of the opposed parts about the opening or slit until the joint is finally set by vulcanization. I accomplish this result by pulling the parts, so to speak, against the closing-mold-supporting-walls instead'of pushing the parts as is the usual practice, thereby obviating thenecessity of a second core or inner support and the time and trouble of placing it in position and removing it from the neck of the bottle after the closure has been effected.

In order to produce the desired pull of the rubber parts. I place the vulcanized rubber about the slit under tension in a direction transversely of the supporting walls,

hold the rubber parts against their supporting walls. To provide for this tension in the preferred embodiment of my invention, I form upon the Walls of the slit or opening opposed flanges 1212 and place these under a tension during the closing or vulcanizing operation. The tension is attained in the preferred'embodiment by providing the flanges with marginal locking beads 1313 which servet-o lock the flanges in a transversely stretched or tensioned state within the closing mold sections 10-10. The mold sections 10 have suitable cavities formed therein for forming the flanges 12-12 and locking beads 13-l3. stance, these flanges and beads are interrupt-1v ed midway of their lengths to provide for the usual tab 3 which extends-from the side walls of the bottle. The tab is preferably formed in sections extending in oppositely 130 In the present in- 7 is "formed by lugs projecting from the mold sections, for suspending the bottle in inverted position in the usual manner when not in use.

The closing and tensioning mold 10 is provided with cavities similar to those in the forming mold for receiving the flanges 12-42, and beads 13-13. It is further provided with a pin 15 for mounting the tab thereon. In this tensioning mold however the cavities for receiving the flanges 12-12 are somewhat wider than the flanges themselves so that when the beads 1313 are forced into their respective cavities the necessary stretch will be produced in the alrcady-vululnixed rubber composing the flanges. spaced from the supporting walls 1111 than is the orifice 14 from the walls about the slit, thereby producing a correspomling stretch in the tab when mounting it upon the pin 15. The stretch in the rubber composingtlie tab and flanges serves to pull and holdjthe base of the bottle firmly and continually against the supporting walls 11.

In forming the slit 9, it must be of suitioient length to permit the withdrawal of the core therethrongh. I The slit need not be as long as the width of the core by any means for the vulcanized rubber about the slit will ol'wiously permit of stretching to a considerable extent to facilitate the withdrawal of the core. In this connection however the elasticity of the vulcanized rubber material composing the bottle must be taken into consideration. It is desirable to produce as small a slit as is feasible and therefore maximum stretching must be resorted to with the attendant possibility of tearing the slit at the ends. To provide against this and to produce a stronger closure in the finished product, 1 preferably continue the fianges-1212 and beads Iii-13 for substa'ntialulistances beyond the ends of thc opening, and as the tongue 6 does not intercept these extending end portions, their op- Iposmg faces are consequently brought togethcr, when the mold sections 10 are closed.'

and are v' ulcanized together siinultanemisly with'the vulcanization of the material composing the body of the bottle. The slit therefore is formcdnot only by the margin of the bottle. but also by the opposed flanges and heads, therebyniaking a very strong opening eliminating any danger of tearing the body portion ofthe bottle when withdrawing the core.

In practising my method, the bottle having been formed and vulcanized in the molds 10. it iswithdrawn therefrom and the core rcmovcd through the slit. The base of the bottle containing the slit'is then placed between the closing'and' tensioning mold 'SQr- Likewise the pin 15 is furthertions 1010 with a strip 16 of vnlcanizable rubber inserted between the flanges 12-'1'2 and another strip 17 between the members of the tab 3. The strips may be conv'cniently circular in cross-section, and the latter strip is preferably put between the tab members in the form of a ring mounted upon the has a tendency to i'latten them or stretch thenr transversely. This flattening or stretching transversely would ordinarily result in forcing the margins of the bottle away from tlr'e supporting walls 11-11. On account of the flanges 12-12 being pre viously stretched transvcrselv bythe tensioning mold and held in this condition by the locking beads thecavities formed in the mold sections. the above mentioned tendency for displacement ,of the margins is overcome. and accurate alinement thereof effected, I

The pressure produced by the closing nioldsections 1010 and the heat of vulcanization spreads out or flattens the strip 16 and ring 17, the latter forming a thin layer of rubber between the opposed tab members and the former providing a thin layer of rubber between the opposed walls of the slit, thereby entirely closing the opening. The strip 16 in flattening out flows or travels toward the interior of the bottle and as the pressure upon theflang es 12-12 is more pronounced than that upon the opposed margins of the bottle about the slit. the slit-closing strip of rubber betwecnthe flanges will consequently be of greater density than that'between the sides of the bottle.

1313 coiiperatii'ig with I And furthermore as there is no inner sup inside of the bottle to form astrengthening bank 18 of rubber about the closure.

In the modification shown in 7, the walls 19 of'the slitrare formed to con verge toward the interior of the bottle which increases the resistance to the flow of the closing strip 16 in forming the banlt l8 and thereby produces greater compressioz'i or density of the portion of the closing strip between these walls. I

The bottle in its completed and iinall v vulcanized condition has a flash or tin of rubber extending from its joined edges which represents the over-flowaml is usually found in all molded article. This flash is finallyrcmoved and simultaneously thcrewith. if desired. the beads 1,3-1? are also removed. Part of the flanges 1Q-l2or all of them may be removed if desired' I prefer however to remove only part of the tow 55 under said tension, and intervening vulcan izable rubber to a pressure to produce dliferent degrees of density in said vulcamzable I joined while under said tension and inter- I vemng vulcamzable rubber to pressure and I l fian'ges and to have the parts left intact sure during the vulcanizing treatment.

As many apparently widely different embodiments of this invention may be made without departing from the spirit thereof, it is to be understood that I do not intend to limit myself to the specific form of the invention as set forth except as indicated in the appended claims. i

Having thus described my invention what I claim and desire to protect by Letters Patent is 1. A method of joining vulcanized rubber parts which consists in supporting the parts from, corresponding sides thereof with; the vulcanized surfaces to be joined oppositely disposed to each other with vulcanizable rubber therebetween, subjecting the parts to tension to produce a pull in a direction towvard the said supporting members to maintain close contact of the parts therewlth, and

subjecting the surfaces to be joined while under said tension; andintervening vulcanizable rubber to pressure and to a vulcanizmg treatment.

2. A method of joining vulcanized rubber parts which consists in supporting the parts from corresponding sides thereof against rigid supports having registering support ing faces, and with the vulcanized surfaces to, be joined oppositely disposed to each other with vulcanizable rubber therebetwen, subjecting the parts to tension to. produce a pull in a direction toward their said sup-- ports to maintain close contact of the parts therewith, and subjecting the surfaces to be to a vulcanizing treatment. r

v 3. A method of joining vulcanized rubber parts which consists in supporting the parts from corresponding sides thereof with the vulcanized surfaces to be joined oppositely disposed to each other and with vulcanizable rubber therebetween, subjecting the parts to tension to produce a pull in a direction transversely to the said supports to main tain close contact of the parts therewith, and subjecting the surfaces to be joined while rubber and to a vulcanizing treatment.

parts which consists in supporting the parts from corresponding sides thereof while maintaining the opposite sides unsupported, with the vulcanized surfaces to be joined oppositely disposed toe'ach other and with vul- 4. A method of joining vulcanized rubber I canizable rubber therebetween, subjecting the surfaces to be joined, and [intervening vulcanizable rubber to pressure to permit said vulcanizable rubber to flow toward the said unsupported sides to form-a bank about the joint and finally vulcanizin'g the joint.

- 5. A method of oining vulcanized rubber; parts. whichconsists in subjecting the-parts to the action of a tensioning mold,.-. bringing the vulcanized surfaces .to be joinedv into. oppositely disposed relationship with; vul-; canizable rubber therebetween, and subjecting the parts while under tension and vule canizable rubber to pressure-and to a uul-t canizingtreatment.

6; A method of joining vulcanized rubber parts which consists in. forlninggthe parts;

with locking extensions,subjecting the parts i to the action of atensionmg mold cooperating with said lock-ingparts to maintain the, said vulcanized. rubber, parts in a stretched condition, bringing the vulcanized surfaces; to bejoin'ed into oppositely disposed,.relationship with vulcanizable rubber therebei tween, subjecting the parts and vulcanizable rubber to pressure and; to f. a vulcanizing treatment and finally removing, the locking parts from the jointure.

7 1A meth def joining vulcanized rubber,

parts v -whichconsists in forming .the parts with locking extensions}, supporting the parts/from corresponding sides. thereof in tensioning molds cooperating with said look. ing parts to hold the said vulcanized rubber, parts under tension to produce apull', to maintain close contact of the parts with. their supporting surfaces, bringing the lvuh canized surfaces to be joined into oppositely, disposed relationship with vulcanizable rubber' ,therebetween, subjecting the parts and vulcanizable rubber to pressure andto a vul canizing treatment, and'finallyremoving the locking parts from the joined parts-'1 j A method-0f o' PartsotvuI- 3 cam'zed'rubber e ller which compri es,

placing, the vulcanized surfaces to bejjoined in opposed relation to eachother withvul canizable rubber therebetween stretchin the vulcanized rubberto produce a tension t ere-" in, and finally vulcanizingthe joint while under said tension. 9. A method of joining two arts of-vul-j canlzed rubber together whic comprises placing the vulcanized parts'to be omed in ,opposed'relation toeach other with vuleanizable rubber therebetween stretching the vulcanized rubber to produce a tension there- 7 in, applying pressure upon the joint, and while so pressed and stretched subjecting it to-vulcanizatio'n.

10.-- In the manufacture of rubber articles about a core the stepwhich c'o'mpris'esforr'ning an opening in thew'all of 'the'a'rticle said opening having converging at t ends withdrawing the core oppositely disposed wall through said opening closing said opening throughoutits entire length by inserting vulcanizable rubber between the .walls of said opening throughout its entire length, and finally Vuleanizing said rubber.

11. A method of curing" a portion of a hollow rubber article which comprises fixing parts projecting from an id article, at p-t'ede tel-mined pointsin the mold, putting the projections under tension and then curing while maintaining the tension. i

1:3. A method of elosing'an opening in a hollow rubber article which comprises fixing parts.projecting therefrom adjacent said opening, at pret'loterinined points in the mold, putting said projertions under tension,

and then curing while maintaining the ten slon. o

13. A method of oining two rubber parts together Whieli"i'tmsists in eeleeting a plurality of points on each part from a free end thereof beyond the ]o1nt wlneh when brought to predetermined positions will bring the parts forming th joint into reg- J EREMlAl-l L. MAHONEY. 

